Field
The described embodiments relate to computing devices having memory hierarchies with multiple levels of memory or “multi-level memory hierarchies.” More specifically, the described embodiments relate to techniques for leasing blocks of memory in multi-level memory hierarchies.
Related Art
Some computing devices include two or more levels of memory organized in a multi-level memory hierarchy. In some of these computing devices, some or all of the levels of the multi-level memory hierarchy are implemented using different types of memory (i.e., memory circuits having different architectures, circuit structures, organization, etc.). For example, multi-level memory hierarchies may include some or all of dynamic random access memory (DRAM) or die-stacked DRAM, phase-change memory (PCM), non-volatile memory such as flash, etc. Each type of memory is associated with various characteristics, benefits, and limitations. For example, some types of memory, such as DRAM, enable faster memory accesses, but consume more electrical power, are more expensive, produce more heat, etc. As another example, some types of memory, such as flash memory, are cheaper and more scalable, but are slower to access.
In some cases, objects (data, instructions, etc.) may be stored in levels of multi-level memory hierarchies for which the corresponding type of memory is less than optimal for storing the object. For example, an object that is accessed often may be stored in a slower type of memory—thereby requiring more time for accesses than if the object was stored in a faster type of memory. As another example, an object that takes up a larger amount of space may be stored in a lower-capacity and expensive high-speed type of memory, instead of being stored in a slower, but higher-capacity and cheaper type of memory. Because efficient operation of memory is an important aspect of the overall operation of computing devices, the storage of objects in multi-level memory hierarchies that include different types of memories is a concern.
In the figures, like reference numerals refer to the same figure elements.